Electron discharge device



April 13, 1937f v. I .RoNcl 2,077,156A

ELECTRON DISCHARGE DEVICE Filed April 27, 1935 2 Sheets-Sheet 1 v v *YATTORNEY pril 13, 1937. v. I .-RoNc1 2,077,156l

ELECTRON DI SCHARGE DEVICE FiledvApril 27, b1955 :esmas-sheet'z /N VENTOR 'By VLRONC/ Patented Apr. 13, 1937 e ELEoTEoN DISCHARGE DEVICEVictor L. Ronc, Brooklyn, N. Y., assignor to Bell TelephoneLaboratories, Incorporated, New York, N. Y., a. corporation of New YorkApplication April 27, 1935, Serial No. 18,518

8 Claims.

This invention relates to electron discharge devices and moreparticularly to such devices especially suitable for audio frequencyamplification. I

One object of this invention is to increase the mutual conductance andpower capacity of electron discharge devices.

Another object of this invention is to maintain the space relation ofthe electrodes in electron discharge devices having a large number o-felectrode elements.

In one illustrative embodiment of this invention, an electron dischargedevice comprises a plurality of ilattened helical grids arrangedlaterally adjacent each other and forming an enclosure, and a pluralityof cathode sections disposed one within each of the grids. Each cathodesection may include. a plurality of V-shaped laments arranged in themedial plane of the corresponding grid parallel to the longer sides ofthe grid. The several grids are surrounded by an anode member andanother anode member is disposed within the closure'fo-rmed by thegrids, the two anode members being electrically connected together.

In accordance with one feature of this invention, the anode members arepolygonal, for example, square or hexagonal, in lateral section-so thatthey present parallel electron receiving surfaces in juxtaposition toeach of the grids and cathode sections. The electrode spacings,therefore, may be made relatively small and substantially equal pathsare insured for substantially all electrons emanating from the cathodesections to the anode members so that a high mutual conductance and arelatively large power capacity are obtained.

In accordance with another feature of this invention, the inner anodemember and the cathode sections are supported from a central standard orrod secured to end closure discs on the anode. An insulating member iscarried by the standard or rod and has extending therefrom a pluralityof resilient hook members which engage the apices or bights of thefilaments.

The invention and the several features thereof will be understood moreclearly and fully from the following detailed description with referenceto the accompanying drawings in which:

Fig. l is a perspective View of an electron discharge deviceillustrative of one embodiment of this invention,'a portion of theenclosing vessel and of the outer anode member Abeing bro-ken away toshow details Qf th@ eletrd@ Structure more clearly;

(Cl. Z50- 27 .5)

Fig. 2 is an elevational view of the electrode assembly embodied in thedevice shown in Fig. 1.

4 4, 5 5, and I`-6, respectively, of Fig. 2, show-` ing the severalinsulating members adjacent the lower end of the electrode assembly andthe supporting and tie members associated therewith;

Fig. 7 .is a top view of the insulating member at. the upper end of theelectrode assembly and the. supporting system for the upper end of thecathode'sections;

Fig. 8 is an enlarged detail View in elevationand partly incross-section of the supporting system for the upper end of the cathodesections;

Fig. 9 is an enlarged detail view in elevation of one of the cathode andcontrol grid units; and

Fig. 10 is a View in cross-section of the electrodes in a modificationof the device shown in Fig. 1.

Referring now to the drawings, the electron discharge device shown inFig. l comprises an enclosing vessel'l having a stem I6 which terminatesin a substantially rectangular press Il from which the electrodeassembly is supported.

The electrode assembly, as shown more clearly in Figs. 2 and 3, includesan Outer box-like or square anode member I8, an inner anode member I9 ofsimilar conguration, electrically connected to the outer anode member,aplurality of electrically connected flattened helical grids 20 disposededge-to-edge and each having its longer sides parallel to correspondingjuxtaposed sides of the inner and outer anode members, and a pluralityof electrically connected fllamentary cathode sections 2l disposed onewithin each of the helical grids 20 and preferably in a medial planethereof.. This arrangement enables close spacing of the electrodesandassu-res substantially uniform paths of the same impedance betweenthe cathode sections and the anode members for substantially allelectronsemanating from the cathode so that a high mutual conductancemay be obtained in the device. It also enables the use of a cathode oflarge aggregate area andy anode surfaces in juxtaposition to oppositesurfaces ofthe cathode sections so that a high power output and highoperating eliciency are obtained.

The outer anode member I8 may be formed of two similar opposed U-shapedportions having flangesA 22 and provided with parallel stifen'ingcorrugations or flutes 23. ,'.I'he correspondinganges 22 are securedtogether in face-to-face relation as, for example, by integral tabs 24on one flange extending through apertures 25 in the corresponding flangeand crimped against the latter flange. The joined flanges may beprovided With longitudinal flutes 26 forming grooves in which rigidmetallic supports or rods 21 are held.

An insulating spacer member 28, which may be a sheet or disc of mica,extends across the end of the electrodes remote from the stem I6, and

is supported by the rods 21, whichextend through apertures in themember. The spacer member 28 may be fastened to the supports or rods 21by eyelets, each of which has a head or flange 29 abutting against thelower surface of the spacer member, lingers 36 suitably ailxed, as bywelding, to the supports or rods 21, and other fingers 3l bent againstthe upper surface of the spacer member.Y

Disposed adjacent the other end of the electrodes arel a Aplurality ofparallel insulating spacer members 32, 33, and 34, which also may besheets or discs of mica, and which are maintained in angular relation tothe electrodes by the supports orrods 21. The spacer member 32, shownmore clearly in Fig. 4, is cross-shapedand may be aflixed to thesupportsor rods 21 by eyelets 35 which may be of the same constructionas the eyelets securing the spacer member 28 tov the supports or rods.The spacer member 34, shown more clearly in Fig. 6, is of the same formas the spacer member 32 and is secured to the supports or rods 21 byeyelets 36. The spacer member 33, shown more clearly in Fig. 5, isdisposed substantially midway between the spacer members 32 and 34 andis provided with apertures in which the supports or rods 21 are slidablyfitted. K

The inner anode member I9, as shown more clearly in Fig. 2, may beprovided with longitudinal stiiening corrugations or flutes 31 and withflanged metallic end closure discs 38 and. 39, which may be secured tothe anode member I9 by tabs`40 integral with themember I9 and extendingthrough `apertures in and crimped against the anges of the closuremembers. The inner anode member I 9 is carried by a support or rod 4Iwhich extends through central apertures in the closure members 38 and 39and is rigidly aixed to the closure member 38 by metallic brackets 4-2suitably secured to the support or rod 4I and to the closure member 36,as by welding. The support or rod 4| is rigidly aixed to the spacermembers 32 and 34 by eyelets, each of which has a head 43 bearingagainst one surface of a spacer member, fingers 44 bent against theopposite surface of the corresponding spacer member, andv other ngers 45secured to the support or rod 4I, as by welding. As shown clearly inFigs. 1 and 2, the support or rod 4I extends slidably through a centralaperture in the upper spacer member 28, and, as shown clearly in Figs. 2and 6, is coupled to one of the supports 21 by -a tie wire or rod 46 sothat the inner and outer anode members I9 and I8 respectively areelectrically connected and may be maintained at the same operatingpotential. Relative angular displacement of the inner anode member I9 isprevented by studs 41 and 48 which are secured to the inner anode memberI9 and extend slidably through the spacer members 28 and 32,respectively.

Each of the cathode sections 2| comprises a plurality of V-shaped'portions, as shown more clearly in Fig. 9, each section being disposedin a plane midway between corresponding surfaces of the anode members I8and I9 and parallel thereto. The several cathode sections 2I aresupported in common at the upper end by a suspension system carried bythe central support or rod 4I. The suspension system, as shown moreclearly in Figs. '1 and 8, comprises a pair of insulating plates 49 and50, for example sheets of mica, which are secured to the support or rod4I by an eyelet having a head 5I upon which the plate 50 rests, iingers52 bent against the plate 49, and other fingers, not shown, afxed, as bywelding to the rod or support 4I. The plates 49 and 50 carry a pluralityof resilient metallic members each of which includes a lateral arm 53extending between the plates 49 and 5D, and a downwardly extending hookportion 54 which engages the apex of one of the V-shaped filamentportions. The innerend 55 Qfeach arm 53 passes through a closefittingaperture in the plate 49 and is bent over against the plate 49.

The metallic members may be aiiixed securelyA in position by cementingthe ends 55 to the plate" The ends of the several cathode sections 2|are secured individually to straight wires 56 which extend through'theinsulating spacer members 32, 33, and 34. The lower bights of each ofthe cathode-sections are secured to similar vwires 51 which also extendthrough the spacer members 32, 33, and34 and are bent at their lowerend, as indicated at 58, to anchor the wires 51 to the lowermost spacermember 34. As shown in Fig. 6, adjacent wires 56 are coupled by tiewires or stubs 59 and diametrically opposite pairs of the wires 56 arecoupled by wires 60 secured, as by welding, to the tie wires or stubs59. Each of the wires 66 is secured totwo metallic stubs 6I embedded inthe press I6 and connected to terminal prongs 62 on a base 63 byconductors 64. From this system of connections, it will be apparent thatone end of each of the cathode sections 2I is electrically connected toone of the terminal prongs 62 and. the other end of each of the sections2| is connected to another of the terminal prongs 62 so that the fourcathode sections 2| are electrically in parallel and a relatively lowvoltage source may be used for heating the cathode.

Each of the ilattened helical grids 29 is supported by a pair ofmetallic uprights or rods 65 and 66 to which each turn or a suitablenumber of turns'of the grids are secured as by welding. The uprights orrods 65 are connected in pairs by stubs or wires 61, as shown in Fig. 5,and extend through apertures in the spacer members 28 and 33. The otheruprights or rods 66 are positioned at the ends of an L-shaped slot 68 inthe spacer members 28 and 33 and are free to move laterally so that thegrids 26 mayexpand and contract Without substantial restraint during theoutgassing treatment and also during the operating life of the device.As shown clearly in Figs. 4 and 6, the uprights or rods 65 and 66 do notpass through the insulating disc 32 but are positioned in cut-outportions of this disc so that relatively high insulation is providedbetween the grid supports and the cathode Wires 56 there` adjacent.

The electrode assembly, it will be apparent, may be fabricated as a unitincluding the stem exteriorly of the enclosing vessel. 'I'he electrodesmay be supported within the vessel as a unit by two relatively heavyrigid metallic rods or wires 69 and 'I0 embedded in the press I 1 inaccordance with the disclosure of my copending application, Serial No.740,735, led August 21, 1934. These wires 59 and 'Ill are rigidlysecured to the spacer members 33 and 34 by eyelets 'H and may beconnected to two of the terminal prongs 62 by conductors 'I2 and 13,respectively. 'I'he wire is secured to the tie wire 46 and forms a partof the lead-in system for the anode members I8 and I9. The wire 69 isconnected to two tie Wires 74 and l5, shown more clearly in Fig. 6,which are secured to a pair of grid support rods 65, and thus the wire69 forms a part of the lead-in system for the control electrode, whichis composed of the grids 20.

The invention may be embodied in devices in which the anode members areof other than square form. For example, in one embodiment illustrated inFig. 10, the inner and outer anode members and TI respectively may behexagonal and six iiattened helical grids 'I8 and six M-shapedfilamentary cathodes I9 may be provided. The various electrodes may besupported and electrically connected in a manner similar to theelectrodes in the embodiment illustrated in Fig. 1.

The anode members may, of course, be of other form. For example, theymay have I2 or 24 sides, and a corresponding number of grids and cathodesections may be utilized. Furthermore, it will be understood thatvarious modications may be made in the specic embodiments of theinvention shown and described without depart ing from the scope andspirit of this invention as defined in the appended claims.

What is claimed is:

1. An electron discharge device comprising a pair of polygonal anodemembers disposed one within another and having their corresponding sidesparallel, a plurality of helical grids disposed one between each pair ofcorresponding sides of said anode members, a cathode having a pluralityof sections disposed one within each of said grids, a mount for theinner anode member, and means carried by said mount supporting thecathode sections.

2. An electron discharge device comprising a pair of polygonal anodemembers disposed one within the other and having their correspondingsides parallel, a plurality of iiattened helical grids disposed onebetween each pair of said corresponding sides, the longer sides of eachof said grids being parallel and uniformly spaced from the sides of saidanode members corresponding thereto, and a cathode having a plurality ofsections disposed one within each of said grids, each of said cathodesections including a. plurality of lamentary portions disposed in amedial plane of the corresponding grid and parallel to the sides of saidanode members corresponding thereto.

3. An electron discharge device comprising a pair of anode membersdisposed one within the other, means supporting the outer of said anodemembers, a support for vthe inner of said anode members extendingtherethrough, a plurality of helical grids disposed between said anodemembers and uniformly spaced therefrom, a cathode element within each ofsaid grids, and resilient supporting means extending from said supportfor the inner anode member and engaging the cathode elements.

4. An electron discharge device comprising a hollow anode, a centralstandard supporting said anode and extending therethrough, a cathodeencompassing said anode, anda suspension system for said cathodeincluding an insulating member carried by said standard, exible meansextending from said insulating member and engaging said cathode at oneend thereof, a second insulating member secured to said standard remotefrom said suspension system, and supporting means for the other end ofsaid cathode positioned by said second insulating member.

5. An electron discharge device comprising a pair of anode membersdisposed one within the other, insulating means maintaining said anodemembers in spaced relation, a plurality of supports spaced by saidinsulating means, a plurality of grids carried by said supports anddisposed between said anode members, a cathode having a plurality ofsections disposed one within each of said grids, a support for the innerof said anode members extending therethrough, and means supporting saidcathode sections from the support for said inner anode member.

6. A multi-grid electron discharge device comprising a plurality of gridelements disposed side by side and dening a polygonal boundary, cathodemembers in cooperative relation with said grid elements, an anodedisposed. Within said boundary, said anode including a shell and closurediscs at the ends of said shell, a support for said anode secured to oneof said discs, and means carried by said support mounting said cathodemembers at one end.

7. An electron discharge device comprising a pair of anode membersdisposed one within the other, the inner anode member including a shelland end closure members, a support for said inner anode member extendingthrough said closure members, a support for the outer anode member,insulating means extending across the ends of said anode members andspacing said supports, a plurality of supports extending between saidinsulating means and spaced thereby, a plurality of helical gridscarried by said last mentioned supports, arranged side by side anddisposed between said anode members, a cathode having a plurality ofsections disposed one within each of said grids and encompassed thereby,and a suspension system for said cathode including resilient meanscarried by the' support for said inner anode member and engaging saidsections.

8. An electron discharge device comprising a pair of polygonal anodemembers disposed one Within the other and having their correspondingsides parallel, the inner anode member including a shell and end closuremembers, a support for said inner anode member extending through saidclosure members, supports for the outer anode member, insulating discsextending across opposite ends of said anode members and spacing thesupports for said anode members, a plurality of uprights extendingthrough said insulating discs and spaced thereby, a plurality offlattened helical grids carried by said uprights, each of said gridsbeing disposed between corresponding sides of said anode members andhaving its longer sides parallel thereto, a cathode including aplurality of filament sections disposed one within each of said grids,each of said sections including a plurality of V-shaped laments, meansextending from one of said insulating discs and engaging one end of saidfilaments, and a supporting system including a plurality of resilientmembers carried by the support for said inner anode member and engagingsaid filaments at the other end.

VICTOR L. RONCI.

